The combination of inductive elements and transformer elements of a power converter on a single core structure is referred to as magnetic integration. The consolidated magnetic system, if integrated properly, has the desired characteristics of the original converter circuit. In many instances, magnetic integration will also produce a converter arrangement which achieves reduced voltage stress on semiconductors. Various integrated magnetic power converter circuits and systems have been suggested, such as described in U.S. Pat. Nos. 4,858,093 and 5,208,739, the descriptions of which are hereby incorporated by reference.
A need has arisen for an integrated magnetic power converter with improved gain capability for power factor correction and power converter applications. Additionally, a need has arisen for an integrated magnetic power converter combining multiple magnetic topologies such as, for example, boost, buck-boost, and buck functions onto a single magnetic core, thereby achieving low core loss, minimal output ripple, high gain, reduced core size, and increased power output.